Antiloading compositions and methods of selecting same

ABSTRACT

An antiloading composition includes a first organic compound. The compound has a water contact angle criterion that is less than a water contact angle for zinc stearate. The first compound also satisfies at least one condition selected from the group consisting of a melting point T melt  greater than about 40° C., a coefficient of friction F less than about 0.3, and an antiloading criterion P greater than about 0.3. Another embodiment includes a second organic compound, having a different water contact angle from that of the first organic compound. The composition has a particular water contact angle W° p  that is determined, at least in part, by the independent W° g  of each compound and the proportion of each compound in the composition. Also, an abrasive product includes the antiloading composition. A method of grinding a substrate is disclosed that includes employing effective amount of an antiloading composition. Further disclosed is a method of selecting an antiloading compound.

RELATED APPLICATIONS

This application is a Divisional of U.S. application Ser. No.10/688,833, filed Oct. 17, 2003. The entire teachings of the aboveapplication are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Generally, abrasive products comprise abrasive particles bonded togetherwith a binder to a supporting substrate. For example, an abrasiveproduct can comprise a layer of abrasive particles bound to a substrate,where the substrate can be a flexible substrate such as fabric or paperbacking, a non-woven support, and the like. Such products are employedto abrade a variety of work surfaces including metal, metal alloys,glass, wood, paint, plastics, body filler, primer, and the like.

It is known in the art that abrasive products are subject to “loading”,wherein the “swarf”, or abraded material from the work surface,accumulates on the abrasive surface and between the abrasive particles.Loading is undesirable because it typically reduces the performance ofthe abrasive product. In response, “antiloading” compositions have beendeveloped that reduce the tendency of an abrasive product to accumulateswarf. For example, zinc stearate has long been known as a component ofantiloading compositions. Many classes of compounds have been proposedas components of antiloading compositions. For example, some proposedcomponents of antiloading compositions can include long alkyl chainsattached to polar groups, such as carboxylates, alkylammonium salts,borates, phosphates, phosphonates, sulfates, sulfonates, and the like,along with a wide range of counter ions including monovalent anddivalent metal cations, organic counterions, such as tetraalkylammonium,and the like.

However, there is no known teaching in the art as to which of this largeclass of compounds are effective antiloading agents, short ofmanufacturing an abrasive product with each potential compound andperforming a time consuming series of abrasion tests. Many proposedcompounds are actually ineffective antiloading agents.

Furthermore, some agents known to be effective for antiloading result inunacceptable contamination of the work surface, e.g., commonly leadingto defects in a subsequent coating step. For example, use of zincstearate in finishing abrasives in the auto industry leads tocontamination of the primer surface, requiring an additional cleaningstep to prepare the primer for a subsequent coat of paint.

Also, some antiloading agents that are known to be effective, such aszinc stearate, are insoluble in water. As a result, manufacturing anabrasive product with a water-insoluble antiloading agent can requireorganic solvents or additional additives and/or processing steps.

Thus, there is a need for antiloading agents that are effective, thatare easily incorporated into an abrasive product, and that minimizecontamination of the work surface. Further, there is a need for a methodof selecting effective antiloading compounds.

SUMMARY OF THE INVENTION

It has now been found that certain compounds can be effectiveantiloading agents, particularly compounds, such as anionic surfactants,that satisfy certain criteria, as demonstrated in Examples 1-5.

An antiloading composition includes a first organic compound. Thecompound has a water contact angle criterion W°_(g) that is less than awater contact angle W°_(z) for zinc stearate. The first compoundsatisfies at least one condition selected from the group consisting of amelting point T_(melt) greater than about 40° C., a dynamic coefficientof friction F less than about 0.5, and an antiloading criterion Pgreater than about 0.2.

Another embodiment includes a second organic compound, having a W°_(g)different from that of the first organic compound. The composition has aparticular water contact angle W°_(p) that is determined, at least inpart, by the independent W°_(g) of each compound and the proportion ofeach compound in the composition.

An abrasive product includes the antiloading composition.

A method of grinding a substrate includes grinding a work surface byapplying an abrasive product to the work surface to create work surfaceswarf, and providing an effective amount of an antiloading compositionat the interface between the abrasive product and the work surfaceswarf.

Another embodiment of the method includes grinding the substrate to aparticular water contact angle W°_(p) by employing the second organiccompound.

A method of selecting an antiloading compound includes selecting thefirst organic compound. Another embodiment of the method includesselecting the second compound, and determining a proportion for eachcompound, whereby a composition comprising the compounds in theproportions has a particular water contact angle W°_(p) that is due, atleast in part, to the W°_(g) of each compound and the proportionthereof.

The advantages of the embodiments disclosed herein are significant. Byproviding effective antiloading compositions, the efficiency andeffectiveness of abrasion products and methods are improved, therebyreducing the cost and improving the quality of the work product. Byproviding antiloading compositions which lead to ground surfaces withdecreased water contact angles W°_(g), the manufacture of abrasiveproducts incorporating antiloading compositions is eased, and thecontamination of work surfaces is reduced, particularly for worksurfaces to be coated after abrasion, e.g., with paint, varnish, powdercoat, and the like. By providing antiloading compositions that areeffective at a range of temperatures, work surfaces at differenttemperatures can be abraded without requiring temperature modificationand/or multiple products for different temperatures. Furthermore, bygrinding a work surface to a particular water contact angle W°_(p), theground surface can be “fine-tuned” to be compatible with a subsequentcoating. The result is a significant improvement in the versatility,quality, and effectiveness of abrasion products, methods, and workproduct produced therefrom.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts a schematic representation of the measurement of watercontact angle.

FIG. 2 is a plot of antiloading criterion P versus empirical grindingperformance G.

DETAILED DESCRIPTION OF THE INVENTION

The disclosed embodiments are generally related to additives used toincrease the effectiveness of abrasive products, in particular,antiloading compositions that are incorporated into abrasive products. Adescription of various embodiments of the invention follows.

As used herein, an “antiloading composition” includes any organiccompound or salt thereof that can be an effective antiloading agent withrespect to the particular combinations of two or more of the criteriadisclosed herein, such as P, F, T_(melt), ΔT, T_(sub), W°, W°_(g),W°_(z), W°_(p), and the chemical structure of the agent.

As used herein, a water contact angle, e.g., water contact angles W°,W°_(g), W°_(z), and W°_(p), can be determined by one skilled in the artby the method of goniometry. When water is applied to a substrate, thewater contact angle is the angle between the plane of the substrate anda line tangent to the surface of the water at the intersection of thewater and the substrate. FIG. 1 illustrates, for example, water contactangles for values of W° less than 90°, equal to 90°, and greater than90°. This angle can be read by a goniometer. Further experimentaldetails for determining the water contact angle are provided in Example4.

As used herein, the substrate can be any material ground or polished inthe art, e.g., wood, metal, plastics, composites, ceramics, minerals,and the like; and also coatings of such substrates including paints,primers, varnishes, adhesives, powder coats, oxide layers, metalplating, contamination, and the like. A substrate typically includesmetal, wood, or polymeric substrates, either bare or coated withprotective primers, paints, clear coats, and the like.

As used herein, W° is the water contact angle measured for an un-groundsubstrate. W°_(g) is the water contact angle measured for a substrateground in the presence of an effective amount of an antiloadingcompound, e.g., the first organic compound. An “effective amount” is anamount of antiloading compound or antiloading composition sufficient tohave an antiloading effect when present during grinding of a substrate.W°_(z) is the water contact angle measured for a substrate ground in thepresence of an effective amount of zinc stearate. When two such valuesare compared, e.g., when W°_(g) is less than W°_(z), it can mean thatthe respective water contact angles are measured for identicalsubstrates ground with identical abrasives in the presence of aneffective amount of each respective compound, e.g., the first organiccompound and zinc stearate.

In various embodiments, W°_(g) for the first compound is less thanW°_(z), typically less than about 125°, more typically less than about110°, still more typically less than about 100°, yet more typically lessthan about 70°, or less than about 50°. In a particular embodiment,W°_(g) for the first compound is about 0°.

In various embodiments, a particular water contact angle W°_(p), can bedesirable, e.g., if it is an angle that can not be easily achieved byemploying a single antiloading compound, or it is an angle that can beeasily achieved by employing a single compound that is undesirable forother reasons, e.g., cost, toxicity, antiloading performance, and thelike. A composition can contain two or more compounds with differentvalues for W°_(g), combined in a proportion that can achieve theparticular water contact angle W°_(p). When two compounds are employed,at least one compound, e.g., the first organic compound, satisfies theminimum antiloading criteria, e.g., W°_(g) is less than W°_(z) and atleast one condition is satisfied from a melting point T_(melt) greaterthan about 40° C., a coefficient of friction less than about 0.6, and anantiloading criterion P greater than about 0.3. The second compound canbe any effective antiloading compound, for example, the second compoundcan be zinc stearate. In particular embodiments, both the first and thesecond organic compound satisfy the minimum antiloading criteria, e.g.,W°_(g) is less than W°_(z) and at least one condition is satisfied froma melting point T_(melt) greater than about 40° C., a coefficient offriction less than about 0.6, and an antiloading criterion P greaterthan about 0.3.

In a particular embodiment, the particular angle W°_(p) can be selectedto match a subsequent coating, which can reduce defects due tocontamination by the antiloading compound. For example, a water-basedcoating can perform better when the surface is prepared with a lowerW°_(p) compared to a surface prepared for an oil based coating. Forparticular coatings that can be very sensitive to W°_(p), e.g., anemulsion based coating, the W°_(p) can be selected to be about theoptimal value for the coating. In various embodiments, the two or morecompounds can be employed together, e.g., as a composition included inthe abrasive, or a composition applied to the abrasive, the worksurface, or both. In other embodiments, the compounds can be employedseparately, e.g., at least one compound can be included in the abrasiveproduct, or applied to the work surface, or the abrasive, and the like.For example, the abrasive can contain at least one compound, and thesecond compound can be applied to the work surface using, e.g., asolution of an antiloading agent, applied by, for example, a spray gunwhich can be controlled to apply particular amounts. Thus, a singleabrasive can be employed between multiple coatings, and the value ofW°_(p) after each grinding operation can be adjusted by the amount ofthe second compound that is employed.

As used herein, the melting point, T_(melt), of the compound can bedetermined by one skilled in the art by the method of differentialscanning calorimetry (DSC). Further experimental details are provided inExample 3. One skilled in the art can appreciate that in this context,the term “melting point” refers to a thermal transition in the DSC plotthat indicates softening of the compound, i.e., the melting point of acrystalline compound, the softening or liquefaction point of anamorphous compound, and the like. In various embodiments, the meltingpoint of the compound is greater than about 40° C., or more typicallygreater than about 55° C., or alternatively, greater than about 70° C.In particular embodiments, the melting point is greater than about 90°C.

The coefficient of friction F for a compound can be determined bypreparing coated samples and measuring the coefficient of friction at20° C. Experimental details for determining F are provided in Example 2.In various embodiments, the value of F for the compound is less thanabout 0.6, more typically less than about 0.4, or alternatively, lessthan about 0.3. In a particular embodiment, the value of F is less thanabout 0.2.

The antiloading criterion P can be calculated by Eq (1):P=0.68−2.07*F+(3.3E−3*ΔT)+1.58*F ²  (1)

In Eq (1), variable ΔT, in units of ° C., is the differenceT_(melt)−T_(sub), where T_(melt) is the melting point of the compoundand T_(sub) is the temperature of the substrate being ground. Thetemperature of the substrate, T_(sub), can be measured by measuring thetemperature of the work surface by employing a thermometer,thermocouple, or other temperature measuring devices well known to oneskilled in the art. In various embodiments, the value of T_(sub) asemployed to calculate ΔT and P, can be from about 20° C. to about 45°C., or more typically from about 20° C. to about 45° C. In a particularembodiment, T_(sub) is about 45° C.

For example, in various embodiments, the antiloading criterion P has avalue of greater than about 0.2, or alternatively greater than about0.3. In a particular embodiment, P is greater than about 0.5. Furtherdetails for antiloading criterion P are provided in Example 5 and inFIG. 2.

In various embodiments, the variable ΔT is greater than about 20° C.,typically greater than about 30° C., more typically greater than about40° C., or alternatively greater than about 50° C. In a particularembodiment, ΔT is greater than about 75° C.

One skilled in the art can appreciate that many abrading applicationscan occur at temperatures above ambient temperature, i.e., greater thanabout 20° C., due to frictional heating, workpiece baking, and the like.For example, in the automotive industry, during the painting process, acar body typically goes through a paint coating station. The car bodycan typically be heated to greater than ambient temperature at a paintstation, which can be as high as about 43° C. As it exits the station,operators can inspect the body for defects, and identified defects canbe abraded.

One skilled in the art can also appreciate that in testing to selecteffective antiloading compounds, the particular temperatures employed inthe test to calculate P do not limit, per se, the temperatures that aselected compound can be used at. For example, a compound that is testedat 45° C. can be used at temperatures that are higher or lower than 45°C.

One skilled in the art can appreciate that certain antiloading agents,e.g., zinc stearate, can have high values for P. However, one skilled inthe art can also appreciate that many applications of abrasive productscan be contaminated by an antiloading agent that increases the watercontact angle of the substrate. For example, if zinc stearate wasemployed on a surface to be coated with a water-based coating, residualzinc stearate would probably need to be removed from the abraded surfaceor the coating can be less effective at adhering to the surface.

The compounds, e.g., organic compounds that can be effective antiloadingagents typically include surfactants or molecules with surfactant-likeproperties, i.e., molecules with a large hydrophobic group coupled to ahydrophilic group, e.g., anionic surfactants. Typical hydrophobic groupsinclude branched or linear, typically linear aliphatic groups of betweenabout 6 and about 18 carbons. Hydrophobic groups can also includecycloaliphatic groups, aryl groups, and optional heteroatomsubstitutions. Typical hydrophilic groups include polar or easilyionized groups, for example: anions such as carboxylate, sulfate,sulfonate, sulfite, phosphate, phosphonate, phosphate, thiosulfates,thiosulfite, borate, and the like. For example, an anionic surfactantincludes a molecule with a long alkyl chain attached to an anionicgroup, e.g., the C12 alkyl group attached to the sulfate anion group insodium dodecyl sulfate.

Thus, for example, anionic surfactants that can be effective antiloadingagents include compounds of the general formula R-A⁻M⁺, where R is thehydrophobic group, A⁻is the anionic group, and M⁺is a counterion. Oneskilled in the art can appreciate that acceptable variations of theformula include stoichiometric combinations of ions of different oridentical valences, e.g., (R-A⁻)₂M⁺⁺, R-A⁻⁻(M⁺)₂, R-A⁻⁻H⁺M⁺, R-A⁻⁻M⁺⁺,and the like.

R can be a C6-C18 branched or linear, typically linear aliphatic group.R can optionally be interrupted by one or more interrupting groups,and/or be substituted, provided that the resulting compound continues tobe an effective antiloading agent according to the criteria disclosedherein. Suitable substituents can include, for example, —F, —Cl, —Br,—I, —CN, —NO₂, halogenated C1-C4 alkyl groups, C1-C6 alkoxy groups,cycloalkyl groups, aryl groups, heteroaryl groups, heterocyclic groups,and the like. Suitable interrupting groups can include, for example,—O—, —S—, —(CO)—, —NR^(a)(CO)—, —NR^(a)—, and the like, wherein R^(a) is—H or a small, e.g., C1-C6, alkyl group, or alternatively, an aryl oraralkyl group, e.g., phenyl, benzyl, and the like.

Counterion M⁺ can form a salt with the compound and can be, for example,a metal cation, e.g., Mg⁺⁺, Mn⁺⁺, Zn⁺⁺, Ca⁺⁺, Cu⁺⁺, Na⁺, Li⁺, K⁺, Cs⁺,Rb⁺, and the like, or a non-metallic cation such as sulfonium,phosphonium, ammonium, alkylammonium, arylammonium, imidazolinium, andthe like. In one embodiment, M⁺ can be a metal ion. In anotherembodiment, M⁺ is an alkali metal ion, e.g., Na⁺, Li⁺, K⁺, Cs⁺, or Rb⁺.In a particular embodiment, M⁺ is Na⁺.

The anionic group depicted by A⁻ can include, for example carboxylate,sulfate, sulfonate, sulfite, sulfosuccinate, sarcosinate, sulfoacetate,phosphate, phosphonate, phosphate, thiosulfate, thiosulfite, borate, andthe like. A⁻ can also include carboxylate, sulfate, sulfonate,phosphate, sarcosinate, sulfoacetate, or phosphonate. Alternatively, theanionic group can be sulfate, sarcosinate, sulfoacetate, or betaine(e.g., trimethylglycinyl, e.g., a carboxylate). In another embodiment,the anionic group can be sulfate.

One skilled in the art will know that a sample of such moleculestypically can include a distribution among neutral, i.e., protonated orpartially or fully esterified forms, For example, a carboxylatesurfactant could include one or more of the species R—CO₂ ⁻M⁺, R—CO₂H,and R—CO₂R^(b), wherein R^(b) is a small, e.g., C1-C6, alkyl group, abenzyl group, and the like.

Thus, in various embodiments, the compound can include, for example,compounds represented by formulas R—OSO₃ ⁻M⁺, R—CONR′CH₂CO₂ ⁻M⁺,R—O(CO)CH₂OSO₃ ⁻M⁺, or RCONH(CH₂)₃N+(CH₃)₂CH₂COO— wherein R is C6-C18linear alkyl; R′ is C1-C4 linear alkyl; and M⁺ is an alkali metal ion.In other embodiments, the compound can include sodium lauryl sulfate,sodium decyl sulfate, sodium octyl sulfate, lauramidopropyl betaine, andsodium lauryl sulfoacetate. In a particular embodiment, the compound canbe sodium lauryl sulfate.

As used herein, an abrasive material is any particulate ceramic,mineral, or metallic substance known to one skilled in the art that isemployed to grind workpieces. For example, abrasive materials caninclude alpha alumina (fused or sintered ceramic), silicon carbide,fused alumina/zirconia, cubic boron nitride, diamond and the like aswell as combinations thereof. Abrasive materials are typically affixedto a support substrate, (e.g., a fabric, paper, metal, wood, ceramic, orpolymeric backing); a solid support, (e.g., a grinding wheel, an “emeryboard”), and the like. The material is affixed by combining a binder,e.g., natural or synthetic glues or polymers, and the like with theabrasive material and the support substrate, and the combination is thencured and dried. The antiloading composition can be combined with theseelements at any stage of fabricating the abrasive product. In oneembodiment, the antiloading composition is combined with the binder andabrasive material during manufacture of the abrasive product. In otherembodiments, the antiloading composition is at the interface between theabrasive surface of the final product and the work surface swarf, e.g.,by applying the antiloading composition to the abrasive surface atmanufacture, applying the antiloading composition to the abrasivesurface, applying the compound to the work surface, combinationsthereof, and the like.

The abrasive product, e.g., in the form of nonwoven abrasives, or coatedabrasives, e.g., sandpaper, a grinding wheel, a disc, a strip, a sheet,a sanding belt, a compressed grinding tool, and the like, can beemployed by applying it to the work surface in a grinding motion, e.g.,manually, mechanically, or automatically applying the abrasive, withpressure, to the work surface in a linear, circular, elliptical, orrandom motion, and the like.

A particular embodiment includes an organic surfactant. The watercontact angle criterion W°_(g), for a test substrate ground with anabrasive in the presence of an effective amount of the composition isless than about 20°. Also, the antiloading criterion P for thesurfactant is greater than about 0.3. Typically, the organic surfactantis selected from a group consisting of sodium lauryl sulfate, sodiumdecyl sulfate, sodium octyl sulfate, lauramidopropyl betaine, and sodiumlauryl sulfoacetate. In a particular embodiment, the surfactant issodium lauryl sulfate.

In various embodiments, the first compound is selected to satisfy one ormore of the following sets of conditions selected from the groupconsisting of:

P is greater than about 0.4;

ΔT is greater than about 5° C.;

F is less than about 0.5;

W°_(g) is less than W°_(z);

W°_(g) is less than W°_(z), T_(melt) is greater than about 40° C., and Fis less than about 0.5;

W°_(g) is about equal to W°, T_(melt) is greater than about 40° C., andF is less than about 0.5; and

ΔT is greater than about 5° C., F is less than about 0.5, and W°_(g) isabout equal to W°.

EXEMPLIFICATION

The following examples are provided to illustrate the principles of theembodiments, and are not intended to be limiting in any way.

Example 1 Measurement of Empirical Grinding Performance

A commercial abrasive product that contained no initial antiloadingcomposition, Norton A270 P500 sandpaper (Norton Abrasives, Worcester,Mass.), was employed for all tests. The experimental anti-loading agents(listed in Table 1; obtained from Stepan Company, Northfield, Ill.;except Arquad 2HT-75, Akzo-Nobel, Chicago, Ill.; and Rhodapon LM andRhodapex PM 603, Rhodia, Cranbury, N.J.) were prepared as 30% solutionsby weight in water and coated onto 5 inch (12.7 cm) diameter discs ofsandpaper with a sponge brush. A back surface of the discs includes amating surface comprising hook and loop fastening material. Theexperimental workpieces were steel panels prepared by painting the steelpanels with a paint selected to be representative of a typical primer inthe automotive industry, e.g., BASF U28 (BASF Corporation, Mount Olive,N.J.). The workpieces were ground by hand using a hand-held foam pad towhich the abrasive disc was attached via the hook and loop fasteningmaterial. The downward force exerted on the abrasive against theworkpiece was monitored using a single-point load cell (LCAE-45 kg loadcell, Omega Engineering, Inc., Stamford, Conn.) mounted underneath a 50cm×50 cm metal plate. The grinding was performed with the workpiececlamped on top of the metal plate. The downward force was maintained at11 N±1N by monitoring the output from the load cell. The foam pad washeld at an approximately 60° angle relative to an axis projecting normalto the steel panels so that only approximately ⅓ of the abrasive disc'ssurface was in contact with the workpiece. The resulting pressure at theabrading interface was therefore approximately 2.6 kN/m².

An approximately 5 cm diameter area of the workpiece was ground with theabrasive. Sanding was performed by back-and-forth motion of the abrasiveacross the surface of the workpiece that was not previously ground. Arate of sanding of approximately 3 strokes per second was used. Thestroke length was approximately 4 cm. The test was performed in 5-secondincrements for a total of 150 seconds, or to the point where the cutrate dropped to zero, whichever occurred first. Cut rate for eachincrement was reported using an empirical scale of 4 through zero, where4 represented a very aggressive cut rate and zero denoted that theproduct had ceased to cut altogether. The ratings were a result ofvisual evaluation of the amount of material removed and swarf generatedcombined with the amount of resistance to lateral motion felt by theoperator. A high cut rate was reflected in large amounts of swarfgeneration and low resistance to lateral motion. Empirical performance Gin the test was expressed as the sum of all the cut-rate numbers overthe duration of the test. The highest G value that can be achieved inthis test can be defined by 4 (maximum cut rate increment)*30(number oftest increments)=120. In Table 1, the empirical performance results werenormalized resulting in values for G ranging from 0 to 1. The grindingtests were carried out at three values of substrate temperature T_(sub),e.g., at about 21° C., 32° C., and 43° C. The results are provided inTable 1 under G, normalized to the best performance at about 21° C. Theparameters F, ΔT, and P are discussed in Examples 2, 3, and 5,respectively.

Table 2 shows the performance of sandpaper coated with sodium laurylsulfate (Stepanol VA-100) versus zinc stearate and versus no coating.The total performance of each material is equal to the sum of allratings over the 150 second test. The values for G, obtained bynormalizing relative to the best-performing product in Table 1, are alsoshown in Table 2. The sandpaper coated with sodium lauryl sulfateperformed better than the sandpaper coated with zinc stearate, which inturn performed better than uncoated sandpaper.

Example 2 Measurement of Coefficient of Friction

The coefficient of friction F for a compound was determined by preparingcoated samples and measuring the coefficient of friction at about 20° C.Chemicals to be tested were coated by hand onto 0.127 mm (millimeter)polyester film (Melinex®, DuPont Teijin Films, Hopewell, Va.) using a12.7 cm (centimeter) 8-path wet film applicator (Model AP-25SS, Paul N.Gardner Company, Inc., Pompano Beach, Fla.) with a 0.127 mm gap setting.If the antiloading agent was provided in a liquid solution, it wascoated directly. If it was solid and water-soluble, it was dissolved inapproximately 10 parts water by weight prior to coating (if the solutionwas not clear, more water was added and the solution was heated untilthe solution became clear, indicating that the agent can be fullydissolved). The coating was then allowed to dry inside an oven set at80° C. for 4 hours to remove at least a portion of any remainingsolvents. For zinc stearate, which is a solid at room temperature and iswater insoluble, the powder was dispersed into Stoddard solvent (CAS#8052-41-3) and then coated onto the film following the former procedure.The coated material was placed inside an oven at 145° C. for 30 minutesto fuse the stearate powder onto the film. After drying in the oven, allcoated samples were conditioned at room temperature for at least 40hours prior to testing.

Once the samples were prepared, the coefficient of friction was measuredby sliding coated material across itself. The apparatus used was aMonitor/Slip & Friction Model 32-26 (Testing Machine, Inc., Amityville,N.Y.). A strip of film coated with the antiloading agent was cut andmounted to fit a 6.35 cm square sled weighing 200 grams. The sled wasdragged across another strip of coated film according to the standardtest method described in ASTM D 1894-01 (American Society for Testingand Materials, West Conshohocken, Pa.). The strips of coated film wereoriented such that the two coated surfaces are in contact as they slidepast one another. The F values are provided in Table 1. TABLE 1 DataShows Performance of Antiloading Compounds Trade Name Supplier ChemicalName or Class F T_(melt) (° C.) ΔT (° C.) P G T_(sub) = 21° C. StepanolWAT Stepan TEA Lauryl Sulfate 0.98 20 −1 0.17 0.04 Stepanol WA-100Stepan Sodium Lauryl Sulfate 0.10 96 75 0.78 0.99 Stepanol AM StepanAmmonium Lauryl Sulfate 0.25 30 9 0.26 0.15 Steol CS-460 Stepan SodiumLaureth Sulfate 0.88 21 0 0.18 0.07 Rhodapex PS-603 Rhodia SodiumC12-C15 Pareth Sulfate 0.75 28 7 0.26 0.17 Polystep B-25 Stepan SodiumDecyl Sulfate 0.07 94 73 0.63 1.00 Polystep A-16 Stepan Branched sodiumdodecylbenzene sulfonate 0.40 46 25 0.29 0.11 Maprosyl 30 Stepan SodiumLauroyl Sarcosinate 0.17 75 54 0.53 0.76 Lathanol LAL Stepan SodiumLauryl Sulfoacetate 0.20 72 51 0.58 0.31 Amphosol LB StepanLauramidopropyl Betaine 0.48 125 104 0.47 0.47 Ammonyx 4002 StepanStearalkonium Chloride 0.32 40 19 0.31 0.50 DLG 20A Ferro Zinc stearate0.18 125 104 0.60 0.71 T_(sub) = 32° C. Stepanol WA-100 Stepan SodiumLauryl Sulfate 0.10 96 64 0.71 0.60 Polystep A-16 Stepan Branched sodiumdodecylbenzene sulfonate 0.40 46 14 0.24 0.07 Maprosyl 30 Stepan SodiumLauroyl Sarcosinate 0.17 75 43 0.47 0.53 Lathanol LAL Stepan SodiumLauryl Sulfoacetate 0.20 72 40 0.51 0.28 Amphosol LB StepanLauramidopropyl Betaine 0.48 125 93 0.47 0.31 Ammonyx 4002 StepanStearalkonium Chloride 0.32 40 8 0.24 0.46 DLG 20A Ferro Zinc stearate0.18 125 93 0.54 0.67 T_(sub) = 43° C. Stepanol WAT Stepan TEA LaurylSulfate 0.98 20 −23 −0.10 0.04 Stepanol WA-100 Stepan Sodium LaurylSulfate 0.10 96 53 0.64 0.76 Stepanol AM Stepan Ammonium Lauryl Sulfate0.25 30 −13 0.06 0.10 Steol CS-460 Stepan Sodium Laureth Sulfate 0.88 21−22 −0.09 0.08 Rhodapex PS-603 Rhodia Sodium C12-C15 Pareth Sulfate 0.7528 −15 0.00 0.11 Polystep B-25 Stepan Sodium Decyl Sulfate 0.07 94 510.53 0.67 Polystep A-16 Stepan Branched sodium dodecylbenzene sulfonate0.40 46 3 0.20 0.07 Maprosyl 30 Stepan Sodium Lauroyl Sarcosinate 0.1775 32 0.41 0.61 Lathanol LAL Stepan Sodium Lauryl Sulfoacetate 0.20 7229 0.43 0.19 Amphosol LB Stepan Lauramidopropyl Betaine 0.48 125 82 0.460.32 Ammonyx 4002 Stepan Stearalkonium Chloride 0.32 40 −3 0.16 0.10 DLG20A Ferro Zinc stearate 0.18 125 82 0.542 0.63

TABLE 2 Data Shows Performance Relative to Uncoated Abrasive (T_(sub) =43° C.) Stepanol Zinc Time (s) WA-100 Stearate Reference 5 4 4 4 10 4 44 15 3 4 4 20 3 3 3 25 3 3 3 30 3 3 3 35 3 3 2 40 3 2 2 45 2 2 1 50 2 21 55 2 1 1 60 2 1 1 65 2 1 0 70 2 1 75 2 1 80 2 1 85 2 1 90 1 1 95 1 1100 1 0 105 1 110 1 115 1 120 1 125 1 130 1 135 1 140 1 145 0 150 Total55 39 29 G rating 0.76 0.54 0.40Key4 Aggressive3 Good2 Fair1 Poor0 No cut

Example 3 DSC Measurement of Melting Points

A sample of approximately 5 mg of each experimental antiloading compoundwas loaded into a differential scanning calorimeter sample cell (modelDSC 2910 TA Instruments New Castle, Del.), and the temperature wasincreased until the melting point was observed. The value for eachcompound is reported in Table 1 as T_(melt), along with ΔT calculatedfrom T_(melt)−T_(sub).

Example 4 Water Contact Angle of Compounds Shows Superior Compounds

1.3 cm-wide strips of steel coated with DuPont U28 primer were groundoffhand with Norton A270 P500 for 20 seconds at a pressure of 66 kN/m²with A270 P500 sandpaper coated with each experimental antiloadingcompound, and the water contact angle was measured with a VCA 2500XEgoniometer (AST Products, Inc, Billerica, Mass.). Six readings weretaken for each ground surface. The water contact angle W°_(g) for eachcompound is reported in Table 3. FIG. 1 illustrates, for example, watercontact angles for values of W° less than 90°, equal to 90°, and greaterthan 90°.

The data illustrate that the water contact angle W° increases afterabrasion to with a sandpaper coated with zinc stearate, e.g., to W°_(z).However, after sanding with certain antiloading compounds such asStepanol WA-100 and Ammonyx 4002, the water contact angle, e.g., W°_(g),can be reduced to about 0°. TABLE 3 Water Contact Angles Resulting fromAbrasion with Antiloading Agents Compound W° Stepanol WA-100 0.0 Ammonyx4002 0.0 Arquad 2HT-75 48.7 Amphosol LB 60.2 Lathanol LAL 66.2 PolystepB-25 99.2 Maprosyl 30 108.2 Zinc Stearate 133.7 Substrate 106.4

Example 5 Grinding Model Predicts Variation in Antiloading Performance

A regression analysis was performed, employing empirical values F and ΔTas the independent variables and the relative grinding performance G asthe dependent variable. Using this approach, Eq. 1 for calculatedperformance P was obtained. Table 1 shows the empirical G values versusthe calculated P values. Table 4 shows the statistics of the regressionanalysis, reflecting the model's ability to account for up to about 75%of the variation in the data. FIG. 2 shows a plot of P versus G. TABLE 4Grinding Performance Model Explains Variation in Data Parameter EstimateStandard Error T Statistic P-Value CONSTANT 0.68 0.097 6.96 1.74 * 10⁻⁷F −2.07 0.432 −4.78 5.45 * 10⁻⁵ ΔT 3.28 * 10⁻³ 8.60 * 10⁻⁴ 3.81 7.28 *10⁻⁴ F² 1.58 0.408 3.88 6.12 * 10⁻⁴R² = 0.75; adjusted R² = 0.72; standard error of estimate = 0.15

While this invention has been particularly shown and described withreferences to various embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the scope of the inventionencompassed by the appended claims.

1. A method of grinding a surface, comprising: grinding a work surfaceby applying an abrasive product to the work surface to create worksurface swarf; and providing an effective amount of an antiloadingcomposition at the interface between the abrasive product and the worksurface swarf; wherein: the abrasive product comprises a binder supportsubstrate, a binder, and an abrasive material bound to the supportsubstrate by the binder; the antiloading composition comprises a firstorganic compound and a second organic compound, wherein each of thefirst and the second organic compounds independently: has a watercontact angle criterion W°_(g) that is less than a water contact angleW°_(z) for zinc stearate; and satisfies at least one condition selectedfrom the group consisting of a melting point T_(melt) greater than about40° C., a dynamic coefficient of friction F less than about 0.4, and anantiloading criterion P greater than about 0.2, and wherein the firstand the second compounds are different, and wherein each of the firstand second organic compounds independently is represented by the formulaR—OSO₃ ⁻M⁺, RCONH(CH₂)₃N+(CH₃)₂CH₂COO—, R—CONR′CH₂CO₂ ⁻M⁺, orR—O(CO)CH₂OSO₃ ⁻M⁺, wherein R is C6-C18 linear alkyl; R′ is C1-C4 linearalkyl; and M⁺ is an alkali metal ion.
 2. The method of claim 1, whereinat least one of the first and the second compound has a W°_(g) less thanabout 100° and satisfies at least one condition selected from the groupconsisting of T_(melt) greater than about 70° C., F less than about 0.4,and P greater than about 0.2.
 3. The method of claim 1, wherein at leastone of the first and the second compound has a W°_(g) less than about70° and satisfies at least one condition selected from the groupconsisting of T_(melt) greater than about 90° C., F less than about 0.3,and P greater than about 0.3.
 4. The method of claim 3, wherein thefirst compound: satisfies each condition T_(melt), F, and P, whereinT_(melt) is greater than about 90° C., F is less than about 0.3, and Pis greater than about 0.3; and is R—OSO₃ ⁻M⁺,RCONH(CH₂)₃N+(CH₃)₂CH₂COO—, R—CONR′CH₂CO₂ ⁻M⁺, or R—O(CO)CH₂OSO₃ ⁻M⁺,wherein R is C6-C18 linear alkyl; R′ is C1-C4 linear alkyl; and M⁺ is analkali metal ion.
 5. The abrasive product of claim 1, wherein W°_(g) forat least one of the first and the second compound is about 0°.
 6. Themethod of claim 1, wherein at least one of the first and the secondcompound is selected from the group consisting of sodium lauryl sulfate,sodium decyl sulfate, sodium octyl sulfate, sodium lauroyl sarcosinate,lauramidopropyl betaine, and sodium lauryl sulfoacetate.
 7. The methodof claim 6, wherein either the first or the second organic compound issodium lauryl sulfate.
 8. The method of claim 1, further comprisinggrinding the surface to a particular water contact angle W°_(p) and whenthe second organic compound has a W°_(g) different from that of thefirst compound, and wherein W°_(p) is determined, at least in part, bythe independent W°_(g) of each compound and the proportion of eachcompound employed.
 9. The method of claim 8, further comprisingselecting W°_(p) for compatibility with a coating to be applied to theground work surface.
 10. The method of claim 8, wherein the step ofproviding the antiloading composition comprises applying at least onecompound to the abrasive product or the work surface.
 11. The method ofclaim 8, wherein the abrasive product comprises at least one of thecompounds.
 12. A method of grinding a surface, comprising: grinding awork surface by applying an abrasive product to the work surface tocreate work surface swarf; and providing an effective amount of anantiloading composition at the interface between the abrasive productand the work surface swarf; wherein: the abrasive product comprises abinder support substrate, a binder, and an abrasive material bound tothe support substrate by the binder; the antiloading compositioncomprises a lauryl sulfate in an amount that reduces the accumulation ofswarf during grinding.
 13. The method of claim 12, wherein the laurylsulfate is sodium lauryl sulfate.
 14. A method of grinding a surface,comprising: grinding a work surface by applying an abrasive product tothe work surface to create work surface swarf; and providing aneffective amount of an antiloading composition at the interface betweenthe abrasive product and the work surface swarf; wherein: the abrasiveproduct comprises a binder support substrate, a binder, and an abrasivematerial bound to the support substrate by the binder; the antiloadingcomposition comprising a lauryl sulfate, wherein the lauryl sulfate isthe only organic antiloading compound included in the antiloadingcomposition.
 15. The abrasive product of claim 14, wherein the laurylsulfate is sodium lauryl sulfate.